An input radio spectrum into an antenna can contain both an intended signal and several, potentially larger, unwanted blockers that can saturate the receiver and reduce its sensitivity. Furthermore, congestion in the wireless frequency spectrum makes it desirable for receiver architecture to be flexible, capable of multi-band operations.
Certain radio receiver architectures contain a family of discrete off-chip filters or high order LC filters that are not favorable in terms of area or cost. Furthermore, front-end filters for certain radio frequency receivers can be bulky and not flexible.
Graphene nano-electro-mechanical (GNEMS) resonators can be more than an order of magnitude smaller (e.g., about 10 μm×10 μm) than certain conventional filters (e.g., film bulk acoustic resonators (FBAR), which can be about 100 μm×100 μm). Furthermore, the resonant frequency of GNEMS can be widely tuned, for example, up to 400%.
While the resonant frequency of GNEMS can be scaled into few GHz's range, it is sometimes desirable to operate GNEMS in a low MHz regime in order to exploit its benefits. However, there are circuit topologies such as passive mixer-first receiver which can be improved when combined with small, cheap, and flexible filtering elements like GNEMS.
Consequently, recognizing a need for radio receiver circuits and methods that can achieve a high quality factor, low area, low cost, and low power while maintaining a high tunability, a combination of conventional circuit topologies with unconventional, i.e., MEMS or NEMS, can provide a receiver with such properties.